Therapeutic drug monitoring
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The authors describe a case of furosemide possibly inhibiting the hypoprothrombinemic effect of warfarin. The initiation of furosemide dosing in a patient receiving a stable dose of warfarin was associated with an 28% decrease in the international normalized ration (INR). ⋯ Consistent with this hypothesis, the authors found that their patient's hematocrit (believed to reflect hydration status) correlated with the INR: r2 = 0.78, p < 0.05. This case provides further evidence suggesting that acute diuresis can decrease the hypoprothrombinemic effect of warfarin.
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Randomized Controlled Trial Clinical Trial
Amikacin Bayesian forecasting in critically ill patients with sepsis and cirrhosis.
This study was designed to determine the population pharmacokinetic parameters of amikacin in two subpopulations of intensive care unit patients with sepsis and cirrhosis and sepsis without cirrhosis. The authors evaluated the usefulness of the obtained parameters to forecast the serum amikacin concentrations in a validation group of patients with sepsis and cirrhosis when used as a priori distribution in a Bayesian forecaster. ⋯ The model derived for patients with cirrhosis used as a priori distribution, with and without feedback, was superior to the model derived for patients with sepsis in forecasting amikacin serum concentrations. The results show the relevance of using the specific model for the subgroup with cirrhosis as a priori distribution in a Bayesian forecaster to obtain a nonbiased prediction with an acceptable precision.
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This laboratory developed a simple and efficient solid-phase extraction method that is combined with high-performance liquid chromatography for rapid and precise therapeutic monitoring of risperidone (Risperdal) in blood concentrations. The solid-phase extraction uses a mixed bed column. ⋯ Advantages of this approach include enhanced speed, sensitivity, and efficiency. A high level of sensitivity may be achieved because of the absence of interference from other drugs, metabolites, or serum components.
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Comparative Study Clinical Trial
Vancomycin serum concentrations in patients with renal dysfunction: a comparison of fluorescence polarization immunoassay and the enzyme-multiplied immunoassay technique.
A study was conducted to determine whether assay-specific quantitative differences exist in the determination of vancomycin serum concentrations obtained from patients with renal dysfunction. Vancomycin serum concentrations were obtained during the first week of therapy for each of three time intervals: 48-96 h, 96-144 h, and 144-192 h after administration of the first dose of vancomycin. Vancomycin serum concentrations were measured using the enzyme-multiplied immunoassay technique (EMIT) and fluorescence polarization immunoassay (FPIA). ⋯ A linear relationship was observed between EMIT and FPIA (EMIT = 0.89 x FPIA - 0.24; r2 = 0.93). No statistically significant differences were observed in the calculated pharmacokinetic parameters between methods. FPIA and EMIT are comparable methods in determining vancomycin serum concentrations within the first week of vancomycin therapy in patients with moderate to severe renal dysfunction.
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Clinical Trial Controlled Clinical Trial
Phenytoin as a risk factor in gingival hyperplasia.
Fifty-four out-patients with epilepsy who had been taking phenytoin for more than one year were examined for gingival hyperplasia. Approximately 76% of patients showed either mild or no gingival hyperplasia. ⋯ There was a tendency for gingival hypertrophy to be associated with both increasing dosage of phenytoin per unit of body weight and the duration of phenytoin administration. All patients followed had a statistically significant progressive trend to increasing gingival hyperplasia with higher total and free phenytoin concentration.